The Monitor’s Engine, Now A Little Less Salty…


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During the past five months the Monitor’s engine has been in electrolytic reduction treatment to reduce corrosion and remove chloride salts.   Analysis of the sodium hydroxide electrolyte solution has shown that the concentration of chloride in the tank had reached 65 ppm (parts per million), meaning that this amount of salt has been removed from the engine and gone into the solution.  This doesn’t sound like a lot until you realize that there are 26,271 gallons of solution in the tank!  Considering this volume, a concentration of 65 ppm (which equals 65 milligrams per liter) is equivalent to 6.5 kilograms or 14.3 pounds of chloride!   Each day, the Monitor’s engine is getting a little less salty- which helps a lot to keep it in good condition for the future!


2 thoughts on “The Monitor’s Engine, Now A Little Less Salty…”

  1. Didn’t you guys start to do the electrolytic reduction of the turret in 2009? What is the chloride ppm in that tank now and how much chloride does that convert to? Also, for us the uninformed, can the chloride be converted into a salt equivalent? My guess is that the 14.4 pounds of chloride in the engine tank would equal roughly 23.4 pounds of salt. Which raises another question. I know various components absorb various amounts of chloride, depending on the type of material and how much these were exposed. I also know that the electrolytic reduction is complete when the chloride ppm reaches a certain level. However, based upon past experience, can you estimate when you believe the reduction will be completed on the engine? How about the turret? Thanks ;^)

    1. Sorry to take awhile to reply to your post, we’ve been knee-deep in the engine! The 14.4 pounds of chloride mentioned is just the weight of the chloride ions, not counting the other half of the salt compound (as sodium) if this is factored in your estimate of 23.4 pounds of salt is about right.

      As for estimating the time it will take to complete desalination of the engine and the turret, as it is likely that the amount of salt release will vary substantially as some components are disassembled, this is difficult to say at this point, but we will have more data as the treatments progress.

      We have not yet started electrolytic reduction of the turret, though it has been under impressed current cathodic protection. A small amount of chloride has been removed into the tap water solution that it is currently in. We expect the pace of turret desalination to increase substantially when we complete its deconcretion and begin electrolytic reduction later this summer, more updates to follow!